Seamless Robotic Arm Link Structure for Torsional Rigidity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing surgical robots face issues with torsional deformations and operating errors due to the accumulation of mechanical deformations in long, multi-link robotic arms, which affect accuracy and maintenance accessibility, and require complex structures for flexible transmission assemblies.
Innovation Solution
A one-piece link design with an inner cavity extending along its length, seamlessly enclosed in section, facilitates smooth force transmission, incorporates flexible transmission assemblies within the cavity, and provides accessible maintenance points through end and side openings, ensuring rigidity and torsional strength while simplifying the structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a multi-link robotic arm structure is used to achieve long reach and flexibility, then the working range and adaptability are improved, but the accumulated torsional deformations increase causing larger operating errors
Solution Approach 1:
The robotic arm is divided into multiple modular links connected by joints, allowing the system to achieve long reach and flexibility while maintaining manageable deformation control in each segment. The segmentation enables independent optimization of each link's structural properties.
Solution Approach 2:
The cross-sectional shape parameter of the links is changed from conventional forms to an optimized configuration that provides enhanced torsional stiffness. This parameter change reduces the accumulated torsional deformations across multiple links while maintaining the required working range.
2Strength
If the lower bottom plate is designed with higher rigidity to resist bending moment and torque, then the link strength is improved, but the seam between upper cover and lower bottom plate causes displacement and torsional deformation
Solution Approach 1:
The upper cover and lower bottom plate are merged into a seamless integrated structure, eliminating the seam that caused displacement and torsional deformation. This merging maintains the required rigidity while removing the source of precision degradation.
Solution Approach 2:
The link structure utilizes composite construction with optimized material distribution to achieve high rigidity and torsional strength without requiring seams or joints that would compromise precision. The composite structure allows for tailored mechanical properties in different regions.
3Reliability
If the flexible transmission assembly is secured with bolts on the arc surface of the pulley, then the transmission reliability is improved, but the maintenance accessibility deteriorates due to limited space for tools
Solution Approach 1:
The flexible transmission assembly and pulley are extracted as a removable module from the link structure. This allows the assembly to be easily accessed, removed, maintained, or replaced without disassembling the entire link, while still providing reliable transmission when installed.
Solution Approach 2:
The maintenance accessibility is dynamically optimized by designing the link with movable or removable covers that provide wide access to the flexible transmission assembly during maintenance operations, while maintaining structural integrity during operation.
4Ease of repair
If additional operation openings are added to the lower bottom plate for maintenance access, then the ease of repair is improved, but the structural integrity and rigidity deteriorate
Solution Approach 1:
Instead of adding openings to the load-bearing lower bottom plate, the maintenance access is provided through extracted or removable components such as covers or modules that do not compromise the structural integrity of the main link body.
Solution Approach 2:
The maintenance access is provided through a different dimensional approach - using removable covers or lateral access points rather than openings in the primary load-bearing surfaces, thus maintaining rigidity while enabling repair access.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present disclosure discloses a link, a robotic arm and a robot, the robotic arm includes at least one link which has a length and defines an inner cavity extending in a length direction of the link, and at least a part of the inner cavity is seamlessly enclosed in section perpendicular to the length direction. According to the robotic arm of the present disclosure, since the cross section of the inner cavity of the link is at least partially enclosed, the smooth transmission of force flow and continuity of force can be ensured, and the link having a relative small wall thickness and a relative simple structure can meet the requirements for rigidity and torsional strength.